It is well known to stop production of an oil and/or gas well by means of injecting a fluid of controlled weight and composition down a line and/or valve, which is generally known as a choke and kill system, into the production tubing.
The present invention is directed to a method and apparatus to stop production of an oil and/or gas well by injecting fluid from the annular space between the well casing and the production tubing and into the bore of the production tubing and through a check-type safety valve. The valve is actuated by a minimal amount of annular to tubing pressure differential whereby the well casing is protected from overpressure. The valve is positioned to receive injection fluid by the well pressure.